Spinal cord injury, neurodegenerative diseases, and stroke are high-incidence causes of neuromotor impairments that result in disability due to diminished muscle capacity and/or function. Other causes disabilities resulting from diminished muscle capacity include surgery, cancer, arthritis, and aging associated processes.
In the United States, approximately 10,000 people each year suffer spinal cord injury, and over 230,000 people live with disabilities due to diminished muscle function resulting from spinal cord injury. Diminished muscle function following a spinal cord injury can result in, for example, paralysis, insufficient muscle activity to achieve stepping, inadequate weight-bearing capacity, aberrant gait, uncoordinated movement, and balance deficit. Previously known rehabilitation methods used to treat such disabilities in individuals with spinal cord injury include stretching, strengthening, gait training, and the use of mechanical, electrical, and electromechanical devices. Although such methods often provide minor improvements in motor abilities in the first, post-injury year, such improvements typically plateau at negligible levels. No previously available rehabilitation method is reliably effective to overcome diminished muscle function resulting from spinal cord injury.
In the United States, neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), cerebral palsy, multiple sclerosis, Huntington's disease, Alzheimer's, etc. occur at high incidence, approximately in a range of from one to seven cases per 100,000 people. Diminished muscle function is a frequent symptom of such neurodegenerative diseases, and can result in impaired strength, impaired coordination, impaired mobility, impaired speech, and contracture. Previously known rehabilitation methods used to treat deficits in individuals with neurodegenerative disease include stretching, strengthening, gait training, and the use of mechanical, electrical, and electromechanical devices. But no previously available rehabilitation method is reliably effective to overcome diminished muscle function resulting from neurodegenerative disease.
In the United States, approximately 750,000 people each year have strokes, and over 4 million people live with a stroke induced disability. Diminished muscle function following stroke can develop as a result of motor neuron cell damage and/or death following a blood clot induced ischemic event. Diminished muscle function following stroke can also develop as a result of “learned nonuse,” a phenomenon observed in stroke victims who, shortly after the stroke event, experience failure in attempting to move a body part partially or completely paralyzed, temporarily, by the stroke. The stroke victim learns how to compensate for this partial or complete paralysis by using body parts unaffected or less affected by the stroke to accomplish daily living activities. Such compensatory strategies become habit, and, eventually, the victim does not attempt to move the affected body part, even when it is neurologically possible to do so.
Previously known rehabilitation methods used to treat diminished muscle function in stroke victims include stretching, strengthening, gait training, and the use of mechanical, electrical, and electromechanical devices. But no previously available rehabilitation technique is reliably effective to restore muscle function lost or partially lost as a result of motor neuron cell lesion and/or death. No previously available rehabilitation technique is reliably effective to overcome diminished muscle function resulting from learned nonuse.
Neuromuscular stimulation devices have previously been developed and used in methods for rehabilitating people suffering from disabilities due to diminished muscle function. For instance, Radwan (U.S. Pat. No. 3,387,147) describes a muscle stimulating pulse generator which provides an electric pulse with a relatively high voltage-to-width ratio and a steep wavefront that stimulates muscle contraction. Wyss et al. (U.S. Pat. No. 4,148,321) discloses a muscular therapy device that makes muscles rhythmically contract and relax at a low frequency by modulating the frequency of an electric current delivered to the muscle. Kofskey et al. (U.S. Pat. No. 4,177,819) teaches an apparatus for stimulating a muscle for 2 to 20 seconds at 2 to 50 second intervals using a modulated electric current. The contents of each of U.S. Pat. No. 3,387,147; U.S. Pat. No. 4,148,321; and U.S. Pat. No. 4,177,819 are hereby incorporated by reference in their entireties.
Passive motion devices have previously been developed and used in methods for rehabilitating people suffering from disabilities due to diminished muscle function. For instance, Pecheux (U.S. Pat. No. 4,323,060) describes a motorized splint that supports and provides motion, to a knee joint of a human leg having diminished muscle function and Genovese et al. (U.S. Pat. No. 4,825,852) discloses a similar device programmable to provide a variety of sequences of passive motion for a variety of durations, such as continuous. Wright and Ober (U.S. Pat. No. 4,520,827) describes a continuous passive motion apparatus similar to the Pecheux and Genovese et al. The contents of each of U.S. Pat. No. 4,323,060; U.S. Pat. No. 1,825,852; and U.S. Pat. No. 4,520,827 are hereby incorporated by reference in their entireties.
People suffering from diminished muscle function due to spinal cord injury, neurodegenerative disease, stroke, surgery, cancer, arthritis, aging, etc. face relative inactivity and deterioration of muscles that would otherwise be active. Given that no previously known rehabilitation device or method is reliably effective in rehabilitating diminished muscle function, there is a need for rehabilitation methods and devices effective in restoring diminished muscle function.